Arduino SMS car starter and keyless entry

I always hated summers and winters in my Ford Focus MK1 because it took quite long to cool down or heat up, by the time it did I was already at work. So I decided to fix this, have some fun and learn quite a few things in the process. I started with an Arduino and a GSM Module and slowly built a whole keyless entry, remote start, push to start system for my car with Bluetooth module and key transponder bypass.

It was a lengthy process, mostly because I needed to find all the wires that I wanted in the car’s electrical wiring schematic.

In the end, I achieved what I wanted. Get up in the morning, send an SMS to my car with the word Start and by the time I left the house it was already at the right temperature. Also, when I approached it, my phone would connect automatically to the Bluetooth module and unlock the doors for me or close them if I stepped away from it. I used BT because it was the most reliable solution, I tried it with a pair of NRF24L01 but those were losing the connection constantly. I got in the car, pressed the beautiful Start button from the dash to keep it from stopping after 20 minutes and that was it. Also, if the car wasn’t started by SMS, it would still open the doors for me and it would start with a single press of the button.

For the GSM part, I used a SIM900 module.

For the transponder bypass I used the iDataLink ADS-ALCA. The nice thing about it is that you put it in programming mode and it can “learn” your key transponder. When you “trigger” it, it would send the same information to the car as if your key was present.

I held a presentation about it at Arduino Day 2014 Cluj-Napoca, but for v01 that didn’t include the keyless entry part. Link